Merge with 3.1

diff --cc Lib/multiprocessing/__init__.py
Simple merge

diff --cc Misc/ACKS
Simple merge

diff --cc Misc/NEWS
index 78442fac2fbb3c43a80b86975067b1bbc94b351c,d5c4699b68ec4268f2a272cc6af670f7bb22d01f..bd21c5c71c8edd1a90b881823063558c8f3aa422
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -40,9 -40,10 +40,13 @@@ Core and Builtin
  Library
  -------
  
 +- Issue #11133: fix two cases where inspect.getattr_static can trigger code
 +  execution. Patch by Daniel Urban.
 +
+ - Issue #11569: use absolute path to the sysctl command in multiprocessing to
+   ensure that it will be found regardless of the shell PATH. This ensures
+   that multiprocessing.cpu_count works on default installs of MacOSX.
+ 
  - Issue #11501: disutils.archive_utils.make_zipfile no longer fails if zlib is
    not installed. Instead, the zipfile.ZIP_STORED compression is used to create
    the ZipFile. Patch by Natalia B. Bidart.